Apple recently released macOS Catalina. This new version has many new security requirements that require tweaks to be made by developers in order for things to work properly.
There is a new build of Formloom that is built to work on Catalina.
All versions of Formloom version 4.0.11 and higher will work under Catalina.
Formloom 3 was replaced by Formloom 4 in 2018. Please upgrade if you need Catalina compatibility.